Dimeric phenanthrenoids

Phenanthrenoids are structurally classified into 5 subclasses, namely, phenanthrenes, 9,10-dihydrophenanthrenes, dimeric phenanthrenoids, phenanthrene alkaloids and other phenanthrenoids. 

Most of the dimeric phenanthrenoids are C-C linked between the two units. However, phoyurmanin E (420) from whole plant of Pholidota yunnanensis ROLFE. is connected at C-1 and C-7 through an ether bond [5]. In these studies on the allelochemical interaction, between the wetland plant Juncus acutus and microalgae, six unusual dimeric 9,10-dihydro- phenanthrenoids 426-431, have been isolated and identified [190,191] as having different connection patterns. Fig. (20). 

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